文章基本信息

标题：Iron Isotope Effect and Local Lattice Dynamics in the (Ba, K)Fe₂As₂ Superconductor Studied by Temperature-Dependent EXAFS
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作者：Wangsheng Chu ; Jie Cheng ; Shengqi Chu 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2013
卷号：3
DOI：10.1038/srep01750
出版社：Springer Nature
摘要：Currently available investigations of the isotope effect in Fe-based superconductors are all based on macroscopic resistivity and susceptibility measurements and results are highly controversial. Here we present an investigation of the Fe isotope effect in the (Ba, K)Fe₂As₂ superconductor by temperature-dependent EXAFS in the framework of Einstein model. This method separates the static structural isotope contribution and the local lattice isotope contribution. Results point out the isotope substitution has a negligible effect on inter-atomic distances. On the contrary, both the local vibrations of the Fe-As and the Fe-Fe bonds show strong iron isotope dependence, which is a marker of an “intrinsic” isotope effect. This bulk iron isotope contribution to the local lattice dynamics suggests the local phonons play an important role in the (Ba, K)Fe₂As₂ superconductor and a three-dimensional electron-phonon interaction should be considered to understand the superconducting mechanism of iron-based superconductors.